CA2725476A1 - Mobile communication method - Google Patents
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- CA2725476A1 CA2725476A1 CA2725476A CA2725476A CA2725476A1 CA 2725476 A1 CA2725476 A1 CA 2725476A1 CA 2725476 A CA2725476 A CA 2725476A CA 2725476 A CA2725476 A CA 2725476A CA 2725476 A1 CA2725476 A1 CA 2725476A1
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- 238000000034 method Methods 0.000 title claims abstract description 61
- 238000010295 mobile communication Methods 0.000 title claims abstract description 38
- 238000004891 communication Methods 0.000 claims abstract description 14
- 101000993838 Homo sapiens Keratinocyte differentiation factor 1 Proteins 0.000 description 8
- 102100031728 Keratinocyte differentiation factor 1 Human genes 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000004364 calculation method Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/08—Reselecting an access point
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0819—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s)
- H04L9/083—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0891—Revocation or update of secret information, e.g. encryption key update or rekeying
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
- H04W12/041—Key generation or derivation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
- H04W12/047—Key management, e.g. using generic bootstrapping architecture [GBA] without using a trusted network node as an anchor
- H04W12/0471—Key exchange
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/10—Connection setup
- H04W76/19—Connection re-establishment
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
- H04L2209/80—Wireless
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
- H04W36/0033—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information
- H04W36/0038—Control or signalling for completing the hand-off for data sessions of end-to-end connection with transfer of context information of security context information
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/16—Interfaces between hierarchically similar devices
- H04W92/20—Interfaces between hierarchically similar devices between access points
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
A mobile communication method according to the present invention communicates between a mobile station(UE) and a radio base station (eNB) by using a certain key. The method includes the step of: (A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station (UE) , a first key (KeNB[n+l]) for generating a certain key from a switching center (MME) in a procedure for re-establishment of the mobile station (UE), the certain key to be used for communication between the mobile station (UE) and a next re-establishment target cell for the mobile station (UE).
Description
JNTTD-576-PCT(PPH) DESCRIPTION
Title of the Invention: Mobile communication method Technical Field [0001]
The present invention relates to a mobile communication method for communicating between a mobile station and a radio base station using a certain key.
Background Art [0002]
A conventional mobile communication system of the LTE
(Long Term Evolution) scheme specified by the 3GPP is conf igured to communicate between a mobile station UE and a radio base station eNB using a certain key.
Title of the Invention: Mobile communication method Technical Field [0001]
The present invention relates to a mobile communication method for communicating between a mobile station and a radio base station using a certain key.
Background Art [0002]
A conventional mobile communication system of the LTE
(Long Term Evolution) scheme specified by the 3GPP is conf igured to communicate between a mobile station UE and a radio base station eNB using a certain key.
[0003]
The certain key includes, for example, a key KRRC_CiPh used for "Ciphering" in an RRC protocol, which is a C-plane protocol between the mobile station UE and the radio base station eNB
(Access Stratum, AS), a key KRRCIP used for "Integrity Protection" in the RRC protocol, and a key Kup_ciph used for "Ciphering" in a U-plane protocol between the mobile station UE and the radio base station eNB (Access Stratum, AS) and the like. These certain keys are generated using a first key KeNB .
The certain key includes, for example, a key KRRC_CiPh used for "Ciphering" in an RRC protocol, which is a C-plane protocol between the mobile station UE and the radio base station eNB
(Access Stratum, AS), a key KRRCIP used for "Integrity Protection" in the RRC protocol, and a key Kup_ciph used for "Ciphering" in a U-plane protocol between the mobile station UE and the radio base station eNB (Access Stratum, AS) and the like. These certain keys are generated using a first key KeNB .
[0004]
Using the same key as any of the certain keys and the first key KeNB for a long time is not preferable because it makes the system's security vulnerable. For this reason, a procedure for updating such a certain key or a first key KeNB during handover JNTTD-576-PCT(PPH) is devised by the 3GPP.
Using the same key as any of the certain keys and the first key KeNB for a long time is not preferable because it makes the system's security vulnerable. For this reason, a procedure for updating such a certain key or a first key KeNB during handover JNTTD-576-PCT(PPH) is devised by the 3GPP.
[0005]
Here, operations of a radio base station (Target eNB) managing a re-establishment target cell to acquire a first key KeNB** used for generating a certain key in the re-establishment procedure for a mobile station UE are described referring to Fig. 8.
Here, operations of a radio base station (Target eNB) managing a re-establishment target cell to acquire a first key KeNB** used for generating a certain key in the re-establishment procedure for a mobile station UE are described referring to Fig. 8.
[0006]
As shown in Fig. 8, first, a radio base station (Source eNB) managing a re-establishment source cell generates an intermediate key KeNB*, based on a stored first key KeNB, a parameter "Next Hop", a parameter "Handover Type" representing a handover type and a parameter "Target PCI" representing identification information of a handover target cell.
As shown in Fig. 8, first, a radio base station (Source eNB) managing a re-establishment source cell generates an intermediate key KeNB*, based on a stored first key KeNB, a parameter "Next Hop", a parameter "Handover Type" representing a handover type and a parameter "Target PCI" representing identification information of a handover target cell.
[0007]
Secondly, the radio base station (Source eNB) managing a re-establishment source cell transmits the generated intermediate key KeNB* to the radio base station (Target eNB) managing the re-establishment target cell.
Secondly, the radio base station (Source eNB) managing a re-establishment source cell transmits the generated intermediate key KeNB* to the radio base station (Target eNB) managing the re-establishment target cell.
[0008]
Thirdly, the radio base station (Target eNB) managing the re-establishment target cell generates the first key KeNB** used for genera~ing a certain key at the radio base station (Target eNB) managing the re-establishment target cell, based on the received intermediate key KeNB* and "C-RNTI (Call Radio Network Temporary ID)" allocated by the re-establishment target cell.
Disclosure of the Invention Problem to be Solved by the Invention JNTTD-576-PCT(PPH) [0009]
However, as described above, the conventional re-establishment procedure in the mobile communication system has a problem that both a radio base station (Source eNB) managing re-establishment source cell and radio base station (Target eNB) managing a re-establishment target cell have to use a plurality of parameters and function to generate a first key KeNB** used at the radio base station (Target eNB) managing the re-establishment target cell.
Thirdly, the radio base station (Target eNB) managing the re-establishment target cell generates the first key KeNB** used for genera~ing a certain key at the radio base station (Target eNB) managing the re-establishment target cell, based on the received intermediate key KeNB* and "C-RNTI (Call Radio Network Temporary ID)" allocated by the re-establishment target cell.
Disclosure of the Invention Problem to be Solved by the Invention JNTTD-576-PCT(PPH) [0009]
However, as described above, the conventional re-establishment procedure in the mobile communication system has a problem that both a radio base station (Source eNB) managing re-establishment source cell and radio base station (Target eNB) managing a re-establishment target cell have to use a plurality of parameters and function to generate a first key KeNB** used at the radio base station (Target eNB) managing the re-establishment target cell.
[0010]
In particular, there is a problem that both radio base station (Source eNB) managing a re-establishment source cell and radio base station (Target eNB) managing a re-establishment target cell have to use KeNB conversion functions (Key Derivation Function, KDF) different in parameters for each of the radio base stations, and a mobile station UE also has to be provided with these KDFs, whereby the procedure is complicated.
In particular, there is a problem that both radio base station (Source eNB) managing a re-establishment source cell and radio base station (Target eNB) managing a re-establishment target cell have to use KeNB conversion functions (Key Derivation Function, KDF) different in parameters for each of the radio base stations, and a mobile station UE also has to be provided with these KDFs, whereby the procedure is complicated.
[0011]
Furthermore, it is cumbersome that KeNB needs to be updated according to PCI (Physical Cell ID) of the re-establishment target cell.
Furthermore, it is cumbersome that KeNB needs to be updated according to PCI (Physical Cell ID) of the re-establishment target cell.
[0012]
In particular, in the case where the procedure is dependent on the PCI, when a mobile station UE tries re-establishment to a different cell under control of a radio base station with "UE context" existing at the radio base station, the re-establishment may be rejected due to mismatching of the certain keys between the mobile station UE
and the radio base station.
JNTTD-576-PCT(PPH) [0013]
Furthermore, there is a restriction in flexible changing of the allocation of C-RNTI, since KeNB needs to be updated according to C-RNTI.
In particular, in the case where the procedure is dependent on the PCI, when a mobile station UE tries re-establishment to a different cell under control of a radio base station with "UE context" existing at the radio base station, the re-establishment may be rejected due to mismatching of the certain keys between the mobile station UE
and the radio base station.
JNTTD-576-PCT(PPH) [0013]
Furthermore, there is a restriction in flexible changing of the allocation of C-RNTI, since KeNB needs to be updated according to C-RNTI.
[0014]
Therefore, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a mobile communication method in which a first key used by a radio base station (Target eNB) managing a re-establishment target cell can be generated through a simplified procedure.
Solution to Problem [0015]
A first aspect of the present invention is summarized as a mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method including the step of: (A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station, a first key for generating a certain key from a switching center in the procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a next establishment target cell for the mobile station.
Therefore, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a mobile communication method in which a first key used by a radio base station (Target eNB) managing a re-establishment target cell can be generated through a simplified procedure.
Solution to Problem [0015]
A first aspect of the present invention is summarized as a mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method including the step of: (A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station, a first key for generating a certain key from a switching center in the procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a next establishment target cell for the mobile station.
[0016]
A second aspect of the present invention is summarized as a mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method including the step of: (A) acquiring, at a radio base JNTTD-576-PCT(PPH) station managing a re-establishment target cell for the mobile station, a certain key from a radio base station with which the mobile station has been communicating prior to the re-establishment, in a re-establishment procedure of the mobile station, the certain key being used for communication between the mobile station and the re-establishment target cell for the mobile station.
A second aspect of the present invention is summarized as a mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method including the step of: (A) acquiring, at a radio base JNTTD-576-PCT(PPH) station managing a re-establishment target cell for the mobile station, a certain key from a radio base station with which the mobile station has been communicating prior to the re-establishment, in a re-establishment procedure of the mobile station, the certain key being used for communication between the mobile station and the re-establishment target cell for the mobile station.
[0017]
In the first and second aspect, the mobile communication method can further include the step of: (B) updating, at the mobile station, the first key based on a re-establishment acknowledge signal received from the radio base station, after transmitting a re-establishment request signal to the radio base station.
In the first and second aspect, the mobile communication method can further include the step of: (B) updating, at the mobile station, the first key based on a re-establishment acknowledge signal received from the radio base station, after transmitting a re-establishment request signal to the radio base station.
[0018]
In the first and second aspect, in the step (B) , the first key is updated based on a parameter included in the re-establishment request acknowledge signal.
In the first and second aspect, in the step (B) , the first key is updated based on a parameter included in the re-establishment request acknowledge signal.
[0019]
A third aspect of the present invention is summarized as a radio base station communicating with a mobile station using a certain key, the radio base station including: an acquisition unit configured to acquire a first key for generating a certain key from a switching center in a re-establishment procedure of a mobile station, the certain key to be used for communication between the mobile station and a next re-establishment target cell for the mobile station.
A third aspect of the present invention is summarized as a radio base station communicating with a mobile station using a certain key, the radio base station including: an acquisition unit configured to acquire a first key for generating a certain key from a switching center in a re-establishment procedure of a mobile station, the certain key to be used for communication between the mobile station and a next re-establishment target cell for the mobile station.
[0020]
A fourth aspect of the present invention is summarized JNTTD-576-PCT(PPH) as a radio base station communicating with a mobile station using a certain key, the radio base station including: an acquisition unit configured to acquire a certain key from a radio station with which the mobile station has been communicating prior to the re-establishment, in a procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a re-establishment target cell for the mobile station.
A fourth aspect of the present invention is summarized JNTTD-576-PCT(PPH) as a radio base station communicating with a mobile station using a certain key, the radio base station including: an acquisition unit configured to acquire a certain key from a radio station with which the mobile station has been communicating prior to the re-establishment, in a procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a re-establishment target cell for the mobile station.
[0021]
In the third and fourth aspect, the radio base station can further include: a notifying unit configured to notify a parameter for updating the first key by the mobile station, after receiving a re-establishment request signal from the mobile station, the parameter being included in a re-establishment acknowledge signal.
Brief Description of the Drawings [0023]
[Fig. 1] Fig. 1 is an overall configurational view of a mobile communication system according to a first embodiment of the present invention.
[Fig. 2] Fig. 2 is a diagram showing an example of a hierarchical structure and a calculation procedure of a kccy used in the mobile communication system according to the first embodiment of the present invention.
[Fig. 3] Fig. 3 is a sequence diagram showing an Intra-eNB
re-establishment procedure in the mobile communication system according to the first embodiment of the present invention.
[Fig_ 4] Fig. 4 is a sequence diagram showing an Inter-eNB
JNTTD-576-PCT(PPH) re-establishment procedure in the mobile communication system according to the first embodiment of the present invention.
[Fig. 5] Fig. 5 is a sequence diagram showing an example of a hierarchical structure and a calculation procedure of a key used in a mobile communication system according to a second embodiment of the present invention.
[Fig. 6] Fig. 6 is a sequence diagram showing an Intra-eNB
re-establishment procedure in the mobile communication system according to the second embodiment of the present invention.
[Fig. 71 Fig. 7 is a sequence diagram showing an Inter-eNB
re-establishment procedure in the mobile communication system according to the second embodiment of the present invention.
[Fig. 8] Fig. 8 is a diagram showing an example of the calculation procedure of a key used in a mobile communication system according to a conventional technique.
Best Modes for Carrying Out the Invention [0024]
(Mobile Communication System According to First Embodiment of the Present Invention) A mobile communication system according to a first embodiment of the present invention is described referring to Fig. 1 to Fig. 4.
[0025]
The mobile communication system according to this embodiment is a mobile communication system to which the LTE
scheme is applied, and includes a plurality of switching centers MME#1, MME#2, ... and a plurality of radio base stations eNB#11, eNB#12, eNB#21, eNB#22, ....
JNTTD-576-PCT(PPH) [0026]
For example, a mobile station UE is configured to communicate, in the cell #111 under the control of the radio base station eNB#11, with the radio base station eNB#11 using a certain key described above.
[0027]
Furthermore, in a re-establishment procedure for the mobile station UE, a radio base station managing a re-establishment target cell (for example, the radio base station eNB#12) is configured to acquire first keys KeNB[n+1], KeNB[n+2] and the like for generating a certain key used in communications with the mobile station UE, without using an intermediate key KeNB* generated by a radio base station managing a re-establishment source cell (for example, the radio base station eNB#11).
[0028]
Fig. 2 shows an example of the hierarchical structure and the calculation procedure of a key used in the mobile communication system according to this embodiment (that is, a key used to calculate the certain key).
[0029]
As shown in Fig. 2, a key KRRC IP used for "Integrity Protection" in the RRC protocol, a key KRRC Ciph used for "Ciphering" in the RRC protocol, and a key Kup ciph used for "Ciphering" in the U-plane of AS are generated using a first key KeNB [n] .
[0030]
The first key KeNB[n] is calculated by using a master key KASME from the formulas given below.
JNTTD-576-PCT(PPH) [0031]
KeNB [on] =KDFo (KASME, NAS SN) KeNB [n+1] =KDF1 (KASME, KeNB [n]) , (n>_0 ) Here, the master key KASME is known only to the mobile station UE and the switching center MME, but must not be known to the radio base station eNB.
[0032]
Furthermore, NAS SN is a sequence number (SN) of a NAS
protocol which is the C-plane protocol between the mobile station UE and the switching center MME (Non Access Stratum, NAS).
[0033]
Hereafter, operations of the mobile communication system according to this embodiment are described referring to Fig.
3 and Fig. 4.
[0034]
First, the intra-eNB re-establishment procedure (intra radio base station re-establishment procedure) in the mobile communication system according to this embodiment is described referring to Fig. 3.
[0035]
As shown in Fig. 3, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n]
and "KI (=n)" (step S1001), the radio base station eNB holds KeNB[n] , KeNB[n+1] and "KI (=n) " (step S1002) , and the switching center MME holds KASME, KeNB [n+1] and "K1 (=n) " (step 51003) .
[0036]
In step S1004, where the RRC connection has been established between the mobile station UE and the radio base JNTTD-576-PCT(PPH) station eNB and the Si connection has been established between the radio base station eNB and the switching center MME, the mobile station UE detects radio link failure (RLF) in the RRC
connection described above. For example, the mobile station UE detects the RLF in the following cases.
[0037]
When RSRP (Reference Signal Received Power) in the RRC
connection is lower than a predetermined threshold for a predetermined period of time.
- When the random access procedure is not successful.
When the handover procedure fails.
Thereafter, the mobile station UE performs a cell selection processing in step 51005, and transmits, in step S1006, "RRC Connection Re-establishment Request (re-establishment request signal) " to a selected cell (or the radio base station eNB managing the selected cell) via a common control channel.
[0038]
In step S1007, the radio base station eNB transmits "RRC
Connection Re-establishment (re-establishment acknowledge signal)" to the mobile station UE. The "RRC Connection Re-establishment" may include "KI (=n+l)".
[0039]
Here, the radio base station eNB holds KeNB[n+l] and "KI
(=n+l)" (step S1008).
[0040]
In step S1109, the mobile station UE calculates KeNB[n+1]
from the formula given below and, in step 51010, using such KeNB[n+l], transmits "RRC Connection Re-establishment Complete (re-establishment complete signal)" to the radio base station JNTTD-576-PCT(PPH) eNB.
[0041]
KeNB [n+1] =KDF1 (KASME, KeNB [n] ) Here, the mobile station UE holds KeNB[n+1] and "KI (=n+l) "
(step S1011).
[0042]
In step S1012, the radio base station eNB transmits, to the switching center MME, "Si Path Switch (path switch signal) "
including "KI (=n+l)".
[0043]
In step S1013, the switching center MME calculates KeNB[n+2]
from the formula given below and, in step S1014, transmits, to the radio base station eNB, "Si Path Switch Ack (path switch acknowledge signal) " including KeNB [n+2] and "KI (=n+1)".
[0044]
KeNB [n+2] =KDF1 (KASME, KeNB [n+1] ) Here, the switching center MME holds KASME, KeNB[n+2] and "KI
(=n+l)" (in step S1015).
[0045]
In step 51016, the radio base station eNB receives "Si Path Switch Ack" and holds KeNB [n+1] , KeNB [n+2] and "KI (=n+l) " .
[0046]
That is, here, the radio base station eNB managing the re-establishment target cell acquires the first key KeNB[n+2] for generating a certain key to be used in communications between the mobile station UE and a next re-establishment target cell for the mobile station UE.
[0047]
In step S1017, the radio base station eNB transmits, to JNTTD-576-PCT(PPH) the mobile station UE, "RRC Connection Reconfiguration" and in step 51018, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Reconfiguration Complete".
[0048]
According to the procedure described above, KeNB and the certain key are updated in the Intra-eNB re-establishment procedure.
[0049]
As shown in Fig. 4, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n]
and "KI (=n) " (step 52001) , the radio base station eNB#1 holds KeNB[n] , KeNB[n+,] and "KI (=n) " (step S2002) , and the switching center MME holds KASME, KeNB[n+,] and "Kl (=n)" (step S2003) .
[0050]
In step S2004, the radio base station eNB#1 transmits, to a neighbor radio base station eNB#2, "X2 HO Preparation (handover preparation signal) " including KeNB [n+,] and "KI
(=n+l) ".
[0051]
In step S2005, the radio base station eNB#2 stores the received KeNB[n+,] and "KI (=n+l) " and, in step S2006, transmits, to the radio base station eNB#l, "X2 HO Preparation Ack (handover preparation acknowledge signal)".
[0052]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeNB[n+l] for generating a certain key to be used in communications with the mobile station UE.
[0053]
JNTTD-576-PCT(PPH) In step S2007, where the RRC connection has been established between the mobile station UE and the radio base station eNB#l and the S1 connection has been established between the radio base station eNB#1 and the switching center MME, the mobile station UE detects RLF in the RRC connection described above.
[0054]
Thereafter, the mobile station UE performs a cell selection processing instep S2008, and transmits, instep 52009, "RRC Connection Re-establishment Request (re-establishment request signal)" to a selected cell (or the re-establishment target base station) eNB#2 via a common control channel.
[0055]
In step S2010, the re-establishment target base station eNB#2 transmits "RRC Connection Re-establishment (re-establishment acknowledge signal)" to the mobile station UE. The "RRC Connection Re-establishment" may include "KI
(=n+l) ".
[0056]
In step 52011, the mobile station UE calculates KeNB[n+1]
from the formula given below and, in step 52013, using such KeNB[n+1], transmits "RRC Connection Re-establishment Complete (re-connection complete signal)" to the re-establishment target base station eNB#2.
[0057]
KeNB [n+l] =KDF1 (KASME, KeNB [n] ) Here, the mobile station UE holds KeNB[n+1] and "KI (=n+l) "
(step S2012).
[0058]
JNTTD-576-PCT(PPH) In step S2014, the radio base station eNB#2 transmits, to the switching center MME, "Si Path Switch (path switch signal)" including "KI (=n+l)".
[0059]
In step S2015, the radio base station eNB#2 transmits, to the mobile station UE, "RRC Connection Reconfiguration" and in step S2016, the mobile station UE transmits, to the radio base station eNB#2, "RRC Connection Reconfiguration Complete".
[0060]
In step 52017, the switching center MME calculates KeNB[n+2]
from the formula given below and, in step S2019, transmits, to the re-establishment target base station eNB#2, "Si Path Switch Ack (path switch acknowledge signal) " including KeNB[n+2] and "KI
(=n+l) ".
[0061]
KeNB [n+2] =KDF1 (KASME, KeNB [n+l] ) Here, the switching center MME holds KASME, KeNB[n+2] and "KI
(=n+1)" (step S2018).
[0062]
In step S2010, the re-establishment target base station eNB#2 receives the "Si Path Switch Ack" and holds KeNB [n+1] , KeNB [n+2]
and "KI (=n+1)".
[0063]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeN13 [n+2] for generating a certain key to be used in communications between the mobile station UE and a next re-establishment target cell for the mobile station UE.
[0064]
JNTTD-576-PCT(PPH) According to the procedure described above, KeNB and the certain key are updated in the Intra-eNB re-establishment procedure.
[0065]
(Operations and Effects of Mobile Communication System According to First Embodiment of the Present Invention) In the mobile communication system according to the first embodiment of the present invention, KeN]3[-,+,_] and the like to be used at the radio base station eNB or eNB#2 managing the re-establishment target cell can be generated through a simplified procedure.
[0066]
(Mobile Communication System According to Second Embodiment of the Present Invention) Referring to Fig. 5 to Fig. 7, a mobile communication system according to a second embodiment of the present invention is described by focusing on differences from the above described mobile communication system according to the first embodiment of the present invention.
[0067]
Fig. 5 shows an example of the hierarchical structure and the calculation procedure of a key used in the mobile communication system according to this embodiment (that is, a key used to calculate the certain key).
[0068]
As shown in Fig. 5, a key KRRCIP used for "Integrity Protection" in the RRC protocol, a key KRRC Ciph used for "Ciphering" in the RRC protocol, and a key Kup_ciph used for "Ciphering" in the U-plane of AS are generated using KeNB[n] [m]
JNTTD-576-PCT(PPH) [0069]
KeNB[n] [m] is calculated by using KeNB[n] from the formulas given below.
[0070]
KeNB [n] [0] =KeNB [n]
KeNB [n] [m+l] =KDF2 (KeNB [n] [m] , (m>_0 ) Furthermore, KeNB[n] is calculated from the formulas given below using KASME.
[0071]
KeNB [O] = KDFO (KASME, NAS SN) KeNB [n+1] = KDF1 (KASME, KeNB [n]) , (n>_0 ) Hereafter, operations of the mobile communication system according to this embodiment are described referring to Fig.
6 and Fig. 7.
[0072]
First, the intra-eNB re-establishment procedure (intra radio base station re-establishment procedure) in the mobile communication system according to this embodiment is described referring to Fig. 6.
[0073]
As shown in Fig. 11, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n] , KeNB[n] [m] , "KI (=n) " and "RC (=m) " (step :3001) , the radio base station eNB holds KeNB [n] , KeNB [n+1] , KeNB [n] [m] , "KI (=n) " and "RC
(=m)" (step S3002), and the switching center MME holds KASME, KeNB[n+v and "Kl (=n)" (step S3003) [0074]
In step S3004, where the RRC connection has been established between the mobile station UE and the radio base JNTTD-576-PCT(PPH) station eNB and the Si connection has been established between the radio base station eNB and the switching center MME, the mobile station UE detects radio link failure (RLF) in the RRC
connection described above.
[0075]
Thereafter, the mobile station UE performs a cell selection processing instep S3005, and transmits, instep 53006, "RRC Connection Re-establishment Request (re-establishment request signal) " to a selected cell (or the radio base station eNB managing the selected cell) via a common control channel.
[0076]
In step S3007, the radio base station eNB transmits, to the mobile station UE, "RRC Connection Re-establishment (re-establishment acknowledge signal)" including "KI (=n) " and "RC (=m+l)".
[0077]
Here, in step 53008, the mobile station UE calculates KeNB[n] [m+i] from the formula given below and, in step S3009, holds KeNB [n] / KeNB[n] [m+1] , "KI (=n+l) " and "RC (m+l) " .
[0078]
KeNB [n] [m+1] =KDF2 (KeNB [n] [m] ) Similarly, in step S3010, the radio base station eNB
calculates KeNB[n] from the formula giver below, and it step 53011, holds KeNB [n] , KeNB [n+1] , KeNB [n] [m+1] , "KI (n+l) " and "RC (=m+1)".
[0079]
KeNB [n] [m+1] =KDF2 (KeNB [n] [m] ) In step S3012, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Re-establishment Complete (re-establishment complete signal)" using the JNTTD-576-PCT (PPH) above-mentioned KeNB[n+l]
[0080]
In step S3013, the radio base station eNB transmits, to the mobile station UE, "RRC Connection Reconfiguration", and in step S3014, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Reconfiguration Complete".
[0081]
According to this embodiment, "Path Switch" in the Intra-eNB re-establishment procedure can be eliminated.
[0082]
Secondly, the intra-eNB re-establishment procedure (e-establishment procedure between different mobile stations) in the mobile communication system according to this embodiment is described referring to Fig. 7.
[0083]
As shown in Fig. 7, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n] , KeNB[n] [m] , "KI (=n) " and "RC (=m) " (step S4001) , the radio base station eNB#1 holds KeNB [n] KeNB [n+l] , KeNB [n] [m] , "KI (=n) " and "RC
(=m)" (step S4002), and the switching center MME holds KASME, KeNB[n+11 and "Kl (=n)" (step S4003) [0084]
In step S4004, the radio base station eNB#1 transmits, to a neighbor radio base station eNB#2, "X2 HO Preparation (handover preparation signal)" including KeNB[n+l] and "KI
(=n+l) ".
[0085]
In steps S4005 and S4006, the radio base station eNB#2 stores KeNB[n+l] I KeNB[n+1] [o], "KI (=n+1)" and "RC (=0) ". Here, JNTTD-5766-PCT (PPH) assume KeNB [n+11 [Ol =KeNB [n+11 [0086]
In step S4007, the radio base station eNB#2 transmits, to the radio base station eNB#l, "X2 HO Preparation Ack (handover preparation acknowledge signal)".
[0087]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeNB(n+ll [0]
for generating a certain key to be used in communication with the mobile station HE.
[0088]
In step S4008, where the RRC connection has been established between the mobile station UE and the radio base station eNB#l and the S1 connection has been established between the radio base station eNB#1 and the switching center MME, the mobile station UE detects RLF in the RRC connection described above.
[0089]
Thereafter, the mobile station UE performs a cell selection processing in step S4009, and transmits, instep 54010, "RRC Connection Re-establishment Request (re-establishment request signal)" to a re-establishment target cell (or the re-establishment target radio base station) eNB#2 via a common control channel.
[0090]
In step 54011, the re-establishment target radio base station eNB#2 transmits, to the mobile station HE, "RRC
Connection Re-establishment" including "KI (=n+l)" and "RC
(=0)"
JNTTD-5/6-PCT(PPH) [0091]
In step S4012, the mobile station UE calculates KeNB[n+1]
and KeNB[n+1] [0] from the formulas given below, and in step 54013, holds KeNB [n+1] , KeN]3[n+l] [0] "KI (=n+l) " and "RC (=0) [0092]
KeNB [n+l] =KDF1 (KASME, KeNB [n] ) KeNB [n+l] [0] =KeNB [n+1]
In step S4014, the mobile station UE transmits, to the re-establishment target radio base station eNB#2, "RRC
Connection Re-establishment Complete" using the above mentioned KeNB[n+1] .
[0093]
In step S4015, the re-establishment target radio base station eNB#2 transmits, to the switching center MME, "S1 Path Switch" including "KI (=n+l)".
[0094]
In step S4016, the re-establishment target radio base station eNB#2 transmits, to the mobile station UE, "RRC
Connection Reconfiguration" and in step S4017, the mobile station UE transmits, to the re-establishment target radio base station eNB#2, "RRC Connection Reconfiguration Complete".
[0095]
In step S4018, the switching center MME calculates KeNB [n+2]
from a formula given below, and, in step S4019, holds KKASME, KeNB [n+2] and "KI (=n+l) " .
[0096]
KeNB [n+2] =KDF1 (KASME, KeNB [n+1 ] ) In step S4020, the switching center MME transmits, to the re-establishment target radio base station eNB#2, "Si Path JNTTD-576-PCT(PPH) Switch Ack" including KeNB[n+2] and "KI (=n+l) ".
[0097]
Here, in step S4021, the re-establishment target radio base station eNB#2 holds KeNB [n+l] , KeNB [n+2] , "KI (=n+l) ", KeNB [n+1]
[o]
and "RC (=0)".
[0098]
As shown in Fig. 6 and Fig. 7, by introducing KeNB in updating at the radio base station using the parameter "RC", KeNB can be updated while eliminating an inquiry to the switching center MME.
[0099]
Meanwhile, in the procedures shown in Fig. 6 and Fig. 7, the parameter "RC" may be omitted from "RRC RRC
Re-establishment".
[0100]
When the parameter "RC" is omitted from "RRC RRC
Re-establishment", necessity of incrementing "RC" can be determined by determining whether the parameter "KI" has been incremented or not.
[0101]
If the "KI" has been incremented, "RC" may be reset to "0", whereas if the "KI" has not been incremented, "RC" may be incremented.
[0102]
Alternatively, if the parameter "RC" is omitted from "RRC
RRC Re-establishment", the mobile station UE may, on a trial basis, maintain the present value of "RC", increment "RC" or reset "RC" to "0", and then check "Integrity" with respect to a message received for each of the cases to autonomously JNTTD-576-PCT(PPH) determine which one of the cases is correct.
[0103]
(Modification) Note that operation of the above described switching center MME, the mobile station UE and the radio base station eNB may be implemented by means of hardware, a software module executed by a processor, or a combination of both.
[0104]
The software module may be provided in any type of storage medium such as an RAM (Random Access Memory) , a flash memory, a ROM (Read Only Memory) , an EPROM (Erasable Programmable ROM) , an EEPROM (Electronically Erasable and Programmable ROM), a register, a hard disk, a removable disk, or a CD-ROM.
[0105]
The storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Also, the storage medium may be integrated into the processor. Also, the storage medium and the processor may be provided in an ASIC. The ASIC may be provided in the switching center MME, the mobile station UE and the radio base station eNB. Also, the storage medium and the processor may be provided in the switching center MME, the mobile station UE
and the radio base station eNB as a discrete component.
[0106]
Hereinabove, the present invention has been described in detail using the above embodiment; however, it is apparent to those skilled in the art that the present invention is not limited to the embodiment described herein. Modifications and variations of the present invention can be made without JNTTD-576-PCT(PPH) departing from the spirit and scope of the present invention defined by the description of the scope of claims. Thus, what is described herein is for illustrative purpose, and has no intention whatsoever to limit the present invention.
In the third and fourth aspect, the radio base station can further include: a notifying unit configured to notify a parameter for updating the first key by the mobile station, after receiving a re-establishment request signal from the mobile station, the parameter being included in a re-establishment acknowledge signal.
Brief Description of the Drawings [0023]
[Fig. 1] Fig. 1 is an overall configurational view of a mobile communication system according to a first embodiment of the present invention.
[Fig. 2] Fig. 2 is a diagram showing an example of a hierarchical structure and a calculation procedure of a kccy used in the mobile communication system according to the first embodiment of the present invention.
[Fig. 3] Fig. 3 is a sequence diagram showing an Intra-eNB
re-establishment procedure in the mobile communication system according to the first embodiment of the present invention.
[Fig_ 4] Fig. 4 is a sequence diagram showing an Inter-eNB
JNTTD-576-PCT(PPH) re-establishment procedure in the mobile communication system according to the first embodiment of the present invention.
[Fig. 5] Fig. 5 is a sequence diagram showing an example of a hierarchical structure and a calculation procedure of a key used in a mobile communication system according to a second embodiment of the present invention.
[Fig. 6] Fig. 6 is a sequence diagram showing an Intra-eNB
re-establishment procedure in the mobile communication system according to the second embodiment of the present invention.
[Fig. 71 Fig. 7 is a sequence diagram showing an Inter-eNB
re-establishment procedure in the mobile communication system according to the second embodiment of the present invention.
[Fig. 8] Fig. 8 is a diagram showing an example of the calculation procedure of a key used in a mobile communication system according to a conventional technique.
Best Modes for Carrying Out the Invention [0024]
(Mobile Communication System According to First Embodiment of the Present Invention) A mobile communication system according to a first embodiment of the present invention is described referring to Fig. 1 to Fig. 4.
[0025]
The mobile communication system according to this embodiment is a mobile communication system to which the LTE
scheme is applied, and includes a plurality of switching centers MME#1, MME#2, ... and a plurality of radio base stations eNB#11, eNB#12, eNB#21, eNB#22, ....
JNTTD-576-PCT(PPH) [0026]
For example, a mobile station UE is configured to communicate, in the cell #111 under the control of the radio base station eNB#11, with the radio base station eNB#11 using a certain key described above.
[0027]
Furthermore, in a re-establishment procedure for the mobile station UE, a radio base station managing a re-establishment target cell (for example, the radio base station eNB#12) is configured to acquire first keys KeNB[n+1], KeNB[n+2] and the like for generating a certain key used in communications with the mobile station UE, without using an intermediate key KeNB* generated by a radio base station managing a re-establishment source cell (for example, the radio base station eNB#11).
[0028]
Fig. 2 shows an example of the hierarchical structure and the calculation procedure of a key used in the mobile communication system according to this embodiment (that is, a key used to calculate the certain key).
[0029]
As shown in Fig. 2, a key KRRC IP used for "Integrity Protection" in the RRC protocol, a key KRRC Ciph used for "Ciphering" in the RRC protocol, and a key Kup ciph used for "Ciphering" in the U-plane of AS are generated using a first key KeNB [n] .
[0030]
The first key KeNB[n] is calculated by using a master key KASME from the formulas given below.
JNTTD-576-PCT(PPH) [0031]
KeNB [on] =KDFo (KASME, NAS SN) KeNB [n+1] =KDF1 (KASME, KeNB [n]) , (n>_0 ) Here, the master key KASME is known only to the mobile station UE and the switching center MME, but must not be known to the radio base station eNB.
[0032]
Furthermore, NAS SN is a sequence number (SN) of a NAS
protocol which is the C-plane protocol between the mobile station UE and the switching center MME (Non Access Stratum, NAS).
[0033]
Hereafter, operations of the mobile communication system according to this embodiment are described referring to Fig.
3 and Fig. 4.
[0034]
First, the intra-eNB re-establishment procedure (intra radio base station re-establishment procedure) in the mobile communication system according to this embodiment is described referring to Fig. 3.
[0035]
As shown in Fig. 3, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n]
and "KI (=n)" (step S1001), the radio base station eNB holds KeNB[n] , KeNB[n+1] and "KI (=n) " (step S1002) , and the switching center MME holds KASME, KeNB [n+1] and "K1 (=n) " (step 51003) .
[0036]
In step S1004, where the RRC connection has been established between the mobile station UE and the radio base JNTTD-576-PCT(PPH) station eNB and the Si connection has been established between the radio base station eNB and the switching center MME, the mobile station UE detects radio link failure (RLF) in the RRC
connection described above. For example, the mobile station UE detects the RLF in the following cases.
[0037]
When RSRP (Reference Signal Received Power) in the RRC
connection is lower than a predetermined threshold for a predetermined period of time.
- When the random access procedure is not successful.
When the handover procedure fails.
Thereafter, the mobile station UE performs a cell selection processing in step 51005, and transmits, in step S1006, "RRC Connection Re-establishment Request (re-establishment request signal) " to a selected cell (or the radio base station eNB managing the selected cell) via a common control channel.
[0038]
In step S1007, the radio base station eNB transmits "RRC
Connection Re-establishment (re-establishment acknowledge signal)" to the mobile station UE. The "RRC Connection Re-establishment" may include "KI (=n+l)".
[0039]
Here, the radio base station eNB holds KeNB[n+l] and "KI
(=n+l)" (step S1008).
[0040]
In step S1109, the mobile station UE calculates KeNB[n+1]
from the formula given below and, in step 51010, using such KeNB[n+l], transmits "RRC Connection Re-establishment Complete (re-establishment complete signal)" to the radio base station JNTTD-576-PCT(PPH) eNB.
[0041]
KeNB [n+1] =KDF1 (KASME, KeNB [n] ) Here, the mobile station UE holds KeNB[n+1] and "KI (=n+l) "
(step S1011).
[0042]
In step S1012, the radio base station eNB transmits, to the switching center MME, "Si Path Switch (path switch signal) "
including "KI (=n+l)".
[0043]
In step S1013, the switching center MME calculates KeNB[n+2]
from the formula given below and, in step S1014, transmits, to the radio base station eNB, "Si Path Switch Ack (path switch acknowledge signal) " including KeNB [n+2] and "KI (=n+1)".
[0044]
KeNB [n+2] =KDF1 (KASME, KeNB [n+1] ) Here, the switching center MME holds KASME, KeNB[n+2] and "KI
(=n+l)" (in step S1015).
[0045]
In step 51016, the radio base station eNB receives "Si Path Switch Ack" and holds KeNB [n+1] , KeNB [n+2] and "KI (=n+l) " .
[0046]
That is, here, the radio base station eNB managing the re-establishment target cell acquires the first key KeNB[n+2] for generating a certain key to be used in communications between the mobile station UE and a next re-establishment target cell for the mobile station UE.
[0047]
In step S1017, the radio base station eNB transmits, to JNTTD-576-PCT(PPH) the mobile station UE, "RRC Connection Reconfiguration" and in step 51018, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Reconfiguration Complete".
[0048]
According to the procedure described above, KeNB and the certain key are updated in the Intra-eNB re-establishment procedure.
[0049]
As shown in Fig. 4, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n]
and "KI (=n) " (step 52001) , the radio base station eNB#1 holds KeNB[n] , KeNB[n+,] and "KI (=n) " (step S2002) , and the switching center MME holds KASME, KeNB[n+,] and "Kl (=n)" (step S2003) .
[0050]
In step S2004, the radio base station eNB#1 transmits, to a neighbor radio base station eNB#2, "X2 HO Preparation (handover preparation signal) " including KeNB [n+,] and "KI
(=n+l) ".
[0051]
In step S2005, the radio base station eNB#2 stores the received KeNB[n+,] and "KI (=n+l) " and, in step S2006, transmits, to the radio base station eNB#l, "X2 HO Preparation Ack (handover preparation acknowledge signal)".
[0052]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeNB[n+l] for generating a certain key to be used in communications with the mobile station UE.
[0053]
JNTTD-576-PCT(PPH) In step S2007, where the RRC connection has been established between the mobile station UE and the radio base station eNB#l and the S1 connection has been established between the radio base station eNB#1 and the switching center MME, the mobile station UE detects RLF in the RRC connection described above.
[0054]
Thereafter, the mobile station UE performs a cell selection processing instep S2008, and transmits, instep 52009, "RRC Connection Re-establishment Request (re-establishment request signal)" to a selected cell (or the re-establishment target base station) eNB#2 via a common control channel.
[0055]
In step S2010, the re-establishment target base station eNB#2 transmits "RRC Connection Re-establishment (re-establishment acknowledge signal)" to the mobile station UE. The "RRC Connection Re-establishment" may include "KI
(=n+l) ".
[0056]
In step 52011, the mobile station UE calculates KeNB[n+1]
from the formula given below and, in step 52013, using such KeNB[n+1], transmits "RRC Connection Re-establishment Complete (re-connection complete signal)" to the re-establishment target base station eNB#2.
[0057]
KeNB [n+l] =KDF1 (KASME, KeNB [n] ) Here, the mobile station UE holds KeNB[n+1] and "KI (=n+l) "
(step S2012).
[0058]
JNTTD-576-PCT(PPH) In step S2014, the radio base station eNB#2 transmits, to the switching center MME, "Si Path Switch (path switch signal)" including "KI (=n+l)".
[0059]
In step S2015, the radio base station eNB#2 transmits, to the mobile station UE, "RRC Connection Reconfiguration" and in step S2016, the mobile station UE transmits, to the radio base station eNB#2, "RRC Connection Reconfiguration Complete".
[0060]
In step 52017, the switching center MME calculates KeNB[n+2]
from the formula given below and, in step S2019, transmits, to the re-establishment target base station eNB#2, "Si Path Switch Ack (path switch acknowledge signal) " including KeNB[n+2] and "KI
(=n+l) ".
[0061]
KeNB [n+2] =KDF1 (KASME, KeNB [n+l] ) Here, the switching center MME holds KASME, KeNB[n+2] and "KI
(=n+1)" (step S2018).
[0062]
In step S2010, the re-establishment target base station eNB#2 receives the "Si Path Switch Ack" and holds KeNB [n+1] , KeNB [n+2]
and "KI (=n+1)".
[0063]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeN13 [n+2] for generating a certain key to be used in communications between the mobile station UE and a next re-establishment target cell for the mobile station UE.
[0064]
JNTTD-576-PCT(PPH) According to the procedure described above, KeNB and the certain key are updated in the Intra-eNB re-establishment procedure.
[0065]
(Operations and Effects of Mobile Communication System According to First Embodiment of the Present Invention) In the mobile communication system according to the first embodiment of the present invention, KeN]3[-,+,_] and the like to be used at the radio base station eNB or eNB#2 managing the re-establishment target cell can be generated through a simplified procedure.
[0066]
(Mobile Communication System According to Second Embodiment of the Present Invention) Referring to Fig. 5 to Fig. 7, a mobile communication system according to a second embodiment of the present invention is described by focusing on differences from the above described mobile communication system according to the first embodiment of the present invention.
[0067]
Fig. 5 shows an example of the hierarchical structure and the calculation procedure of a key used in the mobile communication system according to this embodiment (that is, a key used to calculate the certain key).
[0068]
As shown in Fig. 5, a key KRRCIP used for "Integrity Protection" in the RRC protocol, a key KRRC Ciph used for "Ciphering" in the RRC protocol, and a key Kup_ciph used for "Ciphering" in the U-plane of AS are generated using KeNB[n] [m]
JNTTD-576-PCT(PPH) [0069]
KeNB[n] [m] is calculated by using KeNB[n] from the formulas given below.
[0070]
KeNB [n] [0] =KeNB [n]
KeNB [n] [m+l] =KDF2 (KeNB [n] [m] , (m>_0 ) Furthermore, KeNB[n] is calculated from the formulas given below using KASME.
[0071]
KeNB [O] = KDFO (KASME, NAS SN) KeNB [n+1] = KDF1 (KASME, KeNB [n]) , (n>_0 ) Hereafter, operations of the mobile communication system according to this embodiment are described referring to Fig.
6 and Fig. 7.
[0072]
First, the intra-eNB re-establishment procedure (intra radio base station re-establishment procedure) in the mobile communication system according to this embodiment is described referring to Fig. 6.
[0073]
As shown in Fig. 11, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n] , KeNB[n] [m] , "KI (=n) " and "RC (=m) " (step :3001) , the radio base station eNB holds KeNB [n] , KeNB [n+1] , KeNB [n] [m] , "KI (=n) " and "RC
(=m)" (step S3002), and the switching center MME holds KASME, KeNB[n+v and "Kl (=n)" (step S3003) [0074]
In step S3004, where the RRC connection has been established between the mobile station UE and the radio base JNTTD-576-PCT(PPH) station eNB and the Si connection has been established between the radio base station eNB and the switching center MME, the mobile station UE detects radio link failure (RLF) in the RRC
connection described above.
[0075]
Thereafter, the mobile station UE performs a cell selection processing instep S3005, and transmits, instep 53006, "RRC Connection Re-establishment Request (re-establishment request signal) " to a selected cell (or the radio base station eNB managing the selected cell) via a common control channel.
[0076]
In step S3007, the radio base station eNB transmits, to the mobile station UE, "RRC Connection Re-establishment (re-establishment acknowledge signal)" including "KI (=n) " and "RC (=m+l)".
[0077]
Here, in step 53008, the mobile station UE calculates KeNB[n] [m+i] from the formula given below and, in step S3009, holds KeNB [n] / KeNB[n] [m+1] , "KI (=n+l) " and "RC (m+l) " .
[0078]
KeNB [n] [m+1] =KDF2 (KeNB [n] [m] ) Similarly, in step S3010, the radio base station eNB
calculates KeNB[n] from the formula giver below, and it step 53011, holds KeNB [n] , KeNB [n+1] , KeNB [n] [m+1] , "KI (n+l) " and "RC (=m+1)".
[0079]
KeNB [n] [m+1] =KDF2 (KeNB [n] [m] ) In step S3012, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Re-establishment Complete (re-establishment complete signal)" using the JNTTD-576-PCT (PPH) above-mentioned KeNB[n+l]
[0080]
In step S3013, the radio base station eNB transmits, to the mobile station UE, "RRC Connection Reconfiguration", and in step S3014, the mobile station UE transmits, to the radio base station eNB, "RRC Connection Reconfiguration Complete".
[0081]
According to this embodiment, "Path Switch" in the Intra-eNB re-establishment procedure can be eliminated.
[0082]
Secondly, the intra-eNB re-establishment procedure (e-establishment procedure between different mobile stations) in the mobile communication system according to this embodiment is described referring to Fig. 7.
[0083]
As shown in Fig. 7, before starting the intra-eNB
re-establishment procedure, the mobile station UE holds KeNB[n] , KeNB[n] [m] , "KI (=n) " and "RC (=m) " (step S4001) , the radio base station eNB#1 holds KeNB [n] KeNB [n+l] , KeNB [n] [m] , "KI (=n) " and "RC
(=m)" (step S4002), and the switching center MME holds KASME, KeNB[n+11 and "Kl (=n)" (step S4003) [0084]
In step S4004, the radio base station eNB#1 transmits, to a neighbor radio base station eNB#2, "X2 HO Preparation (handover preparation signal)" including KeNB[n+l] and "KI
(=n+l) ".
[0085]
In steps S4005 and S4006, the radio base station eNB#2 stores KeNB[n+l] I KeNB[n+1] [o], "KI (=n+1)" and "RC (=0) ". Here, JNTTD-5766-PCT (PPH) assume KeNB [n+11 [Ol =KeNB [n+11 [0086]
In step S4007, the radio base station eNB#2 transmits, to the radio base station eNB#l, "X2 HO Preparation Ack (handover preparation acknowledge signal)".
[0087]
That is, here, the radio base station eNB#2 managing the re-establishment target cell acquires the first key KeNB(n+ll [0]
for generating a certain key to be used in communication with the mobile station HE.
[0088]
In step S4008, where the RRC connection has been established between the mobile station UE and the radio base station eNB#l and the S1 connection has been established between the radio base station eNB#1 and the switching center MME, the mobile station UE detects RLF in the RRC connection described above.
[0089]
Thereafter, the mobile station UE performs a cell selection processing in step S4009, and transmits, instep 54010, "RRC Connection Re-establishment Request (re-establishment request signal)" to a re-establishment target cell (or the re-establishment target radio base station) eNB#2 via a common control channel.
[0090]
In step 54011, the re-establishment target radio base station eNB#2 transmits, to the mobile station HE, "RRC
Connection Re-establishment" including "KI (=n+l)" and "RC
(=0)"
JNTTD-5/6-PCT(PPH) [0091]
In step S4012, the mobile station UE calculates KeNB[n+1]
and KeNB[n+1] [0] from the formulas given below, and in step 54013, holds KeNB [n+1] , KeN]3[n+l] [0] "KI (=n+l) " and "RC (=0) [0092]
KeNB [n+l] =KDF1 (KASME, KeNB [n] ) KeNB [n+l] [0] =KeNB [n+1]
In step S4014, the mobile station UE transmits, to the re-establishment target radio base station eNB#2, "RRC
Connection Re-establishment Complete" using the above mentioned KeNB[n+1] .
[0093]
In step S4015, the re-establishment target radio base station eNB#2 transmits, to the switching center MME, "S1 Path Switch" including "KI (=n+l)".
[0094]
In step S4016, the re-establishment target radio base station eNB#2 transmits, to the mobile station UE, "RRC
Connection Reconfiguration" and in step S4017, the mobile station UE transmits, to the re-establishment target radio base station eNB#2, "RRC Connection Reconfiguration Complete".
[0095]
In step S4018, the switching center MME calculates KeNB [n+2]
from a formula given below, and, in step S4019, holds KKASME, KeNB [n+2] and "KI (=n+l) " .
[0096]
KeNB [n+2] =KDF1 (KASME, KeNB [n+1 ] ) In step S4020, the switching center MME transmits, to the re-establishment target radio base station eNB#2, "Si Path JNTTD-576-PCT(PPH) Switch Ack" including KeNB[n+2] and "KI (=n+l) ".
[0097]
Here, in step S4021, the re-establishment target radio base station eNB#2 holds KeNB [n+l] , KeNB [n+2] , "KI (=n+l) ", KeNB [n+1]
[o]
and "RC (=0)".
[0098]
As shown in Fig. 6 and Fig. 7, by introducing KeNB in updating at the radio base station using the parameter "RC", KeNB can be updated while eliminating an inquiry to the switching center MME.
[0099]
Meanwhile, in the procedures shown in Fig. 6 and Fig. 7, the parameter "RC" may be omitted from "RRC RRC
Re-establishment".
[0100]
When the parameter "RC" is omitted from "RRC RRC
Re-establishment", necessity of incrementing "RC" can be determined by determining whether the parameter "KI" has been incremented or not.
[0101]
If the "KI" has been incremented, "RC" may be reset to "0", whereas if the "KI" has not been incremented, "RC" may be incremented.
[0102]
Alternatively, if the parameter "RC" is omitted from "RRC
RRC Re-establishment", the mobile station UE may, on a trial basis, maintain the present value of "RC", increment "RC" or reset "RC" to "0", and then check "Integrity" with respect to a message received for each of the cases to autonomously JNTTD-576-PCT(PPH) determine which one of the cases is correct.
[0103]
(Modification) Note that operation of the above described switching center MME, the mobile station UE and the radio base station eNB may be implemented by means of hardware, a software module executed by a processor, or a combination of both.
[0104]
The software module may be provided in any type of storage medium such as an RAM (Random Access Memory) , a flash memory, a ROM (Read Only Memory) , an EPROM (Erasable Programmable ROM) , an EEPROM (Electronically Erasable and Programmable ROM), a register, a hard disk, a removable disk, or a CD-ROM.
[0105]
The storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Also, the storage medium may be integrated into the processor. Also, the storage medium and the processor may be provided in an ASIC. The ASIC may be provided in the switching center MME, the mobile station UE and the radio base station eNB. Also, the storage medium and the processor may be provided in the switching center MME, the mobile station UE
and the radio base station eNB as a discrete component.
[0106]
Hereinabove, the present invention has been described in detail using the above embodiment; however, it is apparent to those skilled in the art that the present invention is not limited to the embodiment described herein. Modifications and variations of the present invention can be made without JNTTD-576-PCT(PPH) departing from the spirit and scope of the present invention defined by the description of the scope of claims. Thus, what is described herein is for illustrative purpose, and has no intention whatsoever to limit the present invention.
Claims (7)
- [1] A mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method comprising the step of:
(A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station, a first key for generating a certain key from a switching center in the procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a next establishment target cell for the mobile station. - [2] A mobile communication method for communicating between a mobile station and a radio base station by using a certain key, the method comprising the step of:
(A) acquiring, at a radio base station managing a re-establishment target cell for the mobile station, a certain key from a radio base station with which the mobile station has been communicating prior to the re-establishment, in a re-establishment procedure of the mobile station, the certain key being used for communication between the mobile station and the re-establishment target cell for the mobile station. - [3] The mobile communication method according to claim 1 or 2, further comprising the step of:
(B) updating, at the mobile station, the first key based on a re-establishment acknowledge signal received from the radio base station, after transmitting a re-establishment request signal to the radio base station. - [4] The mobile communication method according to Claim 3, wherein in the step (B), the first key is updated based on a parameter included in the re-establishment request acknowledge signal.
- [5] A radio base station communicating with a mobile station using a certain key, the radio base station comprising:
an acquisition unit configured to acquire a first key for generating a certain key from a switching center in a re-establishment procedure of a mobile station, the certain key to be used for communication between the mobile station and a next re-establishment target cell for the mobile station. - [6] A radio base station communicating with a mobile station using a certain key, the radio base station comprising:
an acquisition unit configured to acquire a certain key from a radio station with which the mobile station has been communicating prior to the re-establishment, in a procedure for re-establishment of a mobile station, the certain key to be used for communication between the mobile station and a re-establishment target cell for the mobile station. - [7] The radio base station according to claim 5 or 6 further comprising:
a notifying unit configured to notify a parameter for updating the first key by the mobile station, after receiving a re-establishment request signal from the mobile station, the parameter being included in a re-establishment acknowledge signal.
Applications Claiming Priority (3)
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| JP2008169669A JP4443620B2 (en) | 2008-06-27 | 2008-06-27 | Mobile communication method |
| JP2008-169669 | 2008-06-27 | ||
| PCT/JP2009/061746 WO2009157547A1 (en) | 2008-06-27 | 2009-06-26 | Mobile communication method |
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| CA2725476A1 true CA2725476A1 (en) | 2009-12-30 |
| CA2725476C CA2725476C (en) | 2013-03-26 |
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| US7668541B2 (en) | 2003-01-31 | 2010-02-23 | Qualcomm Incorporated | Enhanced techniques for using core based nodes for state transfer |
| US8983468B2 (en) | 2005-12-22 | 2015-03-17 | Qualcomm Incorporated | Communications methods and apparatus using physical attachment point identifiers |
| US8982835B2 (en) | 2005-09-19 | 2015-03-17 | Qualcomm Incorporated | Provision of a move indication to a resource requester |
| US8982778B2 (en) | 2005-09-19 | 2015-03-17 | Qualcomm Incorporated | Packet routing in a wireless communications environment |
| US9078084B2 (en) | 2005-12-22 | 2015-07-07 | Qualcomm Incorporated | Method and apparatus for end node assisted neighbor discovery |
| US9736752B2 (en) | 2005-12-22 | 2017-08-15 | Qualcomm Incorporated | Communications methods and apparatus using physical attachment point identifiers which support dual communications links |
| US9066344B2 (en) | 2005-09-19 | 2015-06-23 | Qualcomm Incorporated | State synchronization of access routers |
| US9083355B2 (en) | 2006-02-24 | 2015-07-14 | Qualcomm Incorporated | Method and apparatus for end node assisted neighbor discovery |
| US9155008B2 (en) | 2007-03-26 | 2015-10-06 | Qualcomm Incorporated | Apparatus and method of performing a handoff in a communication network |
| US8830818B2 (en) | 2007-06-07 | 2014-09-09 | Qualcomm Incorporated | Forward handover under radio link failure |
| US9094173B2 (en) | 2007-06-25 | 2015-07-28 | Qualcomm Incorporated | Recovery from handoff error due to false detection of handoff completion signal at access terminal |
| CN102595399B (en) * | 2008-06-23 | 2017-02-01 | 华为技术有限公司 | Key derivation method, device and system |
| JP4505528B2 (en) * | 2008-09-22 | 2010-07-21 | 株式会社エヌ・ティ・ティ・ドコモ | Mobile communication method |
| CN101945384B (en) * | 2009-07-09 | 2013-06-12 | 中兴通讯股份有限公司 | Method, device and system for processing safe key in reconnection of RRC (Radio Resource Control) |
| US20110268085A1 (en) * | 2009-11-19 | 2011-11-03 | Qualcomm Incorporated | Lte forward handover |
| US8615241B2 (en) | 2010-04-09 | 2013-12-24 | Qualcomm Incorporated | Methods and apparatus for facilitating robust forward handover in long term evolution (LTE) communication systems |
| JP5655710B2 (en) * | 2011-05-31 | 2015-01-21 | 富士通株式会社 | Base station apparatus, communication system and communication method |
| US9049698B2 (en) | 2012-01-18 | 2015-06-02 | Mediatek Inc. | Method of enhanced connection recovery and cell selection |
| JP5993098B2 (en) | 2013-01-11 | 2016-09-14 | エルジー エレクトロニクス インコーポレイティド | Method and apparatus for applying security information in a wireless communication system |
| JP6255615B2 (en) * | 2013-08-07 | 2018-01-10 | 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． | Terminal information reporting method and related devices |
| KR102078866B1 (en) * | 2013-08-09 | 2020-02-19 | 삼성전자주식회사 | SCHEME FOR Security key management for PDCP distribution in dual connectivity |
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| US5887251A (en) * | 1996-10-30 | 1999-03-23 | Ericsson Inc. | Authentication key management for mobile stations |
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| US8046581B2 (en) * | 2002-03-04 | 2011-10-25 | Telespree Communications | Method and apparatus for secure immediate wireless access in a telecommunications network |
| CN1985495A (en) * | 2004-07-15 | 2007-06-20 | 皇家飞利浦电子股份有限公司 | Security system for wireless networks |
| JP4715239B2 (en) * | 2005-03-04 | 2011-07-06 | 沖電気工業株式会社 | Wireless access device, wireless access method, and wireless network |
| US8230212B2 (en) * | 2006-08-29 | 2012-07-24 | Alcatel Lucent | Method of indexing security keys for mobile internet protocol authentication |
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| EP2028890B1 (en) * | 2007-08-12 | 2019-01-02 | LG Electronics Inc. | Handover method with link failure recovery, wireless device and base station for implementing such method |
| ES2562220T3 (en) * | 2007-08-13 | 2016-03-03 | Qualcomm Incorporated | Optimization of delivery in order of data packets during a wireless communication handover |
| CN102595399B (en) * | 2008-06-23 | 2017-02-01 | 华为技术有限公司 | Key derivation method, device and system |
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- 2008-06-27 JP JP2008169669A patent/JP4443620B2/en active Active
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2009
- 2009-06-26 KR KR1020107024049A patent/KR101045560B1/en not_active IP Right Cessation
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| CA2725476C (en) | 2013-03-26 |
| RU2010144012A (en) | 2012-08-10 |
| AU2009263325B2 (en) | 2012-12-13 |
| KR101045560B1 (en) | 2011-07-01 |
| JP2010011242A (en) | 2010-01-14 |
| EP2273808A1 (en) | 2011-01-12 |
| US8229120B2 (en) | 2012-07-24 |
| JP4443620B2 (en) | 2010-03-31 |
| EP2273808A4 (en) | 2011-09-07 |
| KR20100127858A (en) | 2010-12-06 |
| WO2009157547A1 (en) | 2009-12-30 |
| EP2273808B1 (en) | 2012-12-05 |
| AU2009263325A1 (en) | 2009-12-30 |
| US20110124358A1 (en) | 2011-05-26 |
| BRPI0914667A2 (en) | 2015-10-20 |
| ES2398024T3 (en) | 2013-03-13 |
| RU2461985C2 (en) | 2012-09-20 |
| CN102057708A (en) | 2011-05-11 |
| MX2010012287A (en) | 2010-12-01 |
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